Compared with optical density variations, human eyes are more sensitive to color variations. Herein, we develop a multicolor biosensor for organophosphorus pesticides (OPs) detection based on the enzymatic etching of gold nanorods (AuNRs). In the presence of acetylcholinesterase (AChE) and choline oxidase (CHO), the substrate acetylcholine (ACh) is catalyzed to generate H₂O₂. The resultant H₂O₂ etches AuNRs and lead to the etching of AuNRs, accompanying with distinct color changes. OPs inhibit the activity of AChE, which prevent the generation of H₂O₂ and the etching of AuNRs. Visual semi-quantitative determination of OPs is significantly improved due to multiple colors are presented in this biosensor. LSPR shift (ΔW), after and before inhibition, was utilized to quantitatively measure OPs. Under optimum conditions, the LSPR band shift of AuNRs are linearly dependent on the logarithm of inhibitor concentration over the ranges from 0.01 to 50 μg/L and from 1.0 to 500 μg/L, for dichlorvos and demeton, respectively. LOD are much lower than the maximum residue limits specified in the U.S Department of Agriculture and European Union pesticide regulations. They are also lower than those obtained by previously reported colorimetric methods.

与光密度变化相比，人眼对颜色变化更敏感。本文中，我们基于金纳米棒（AuNRs）的酶刻蚀技术开发了一种用于有机磷农药（OPs）检测的多色生物传感器。在乙酰胆碱酯酶（AChE）和胆碱氧化酶（CHO）的存在下，底物乙酰胆碱（ACh）被催化生成H ₂ O ₂。所得的H ₂ O ₂蚀刻AuNRs，并导致AuNRs的蚀刻，并伴有明显的颜色变化。OPs抑制AChE的活性，阻止了H ₂ O _2的产生以及AuNRs的蚀刻。由于在该生物传感器中呈现多种颜色，因此视觉上对OP的半定量测定得到了显着改善。抑制后和抑制前的LSPR位移（ΔW）用于定量测量OP。在最佳条件下，敌敌畏和敌敌畏分别在0.01至50μg/ L和1.0至500μg/ L的范围内，AuNRs的LSPR带位移线性依赖于抑制剂浓度的对数。LOD远低于美国农业部和欧盟农药法规规定的最大残留限量。它们也低于先前报道的比色法获得的那些。